Fig. 4

Carotenoid cleavage by PbLSD in recombinant carotenoid producing E.coli strains. Top panel: The effect of expression of PbLSD in select carotenoid accumulating E. coli strains transformed with pET28b + -PbLSD and induced with IPTG was assessed visually (bottom row of pellets). β-, δ- or ε- carotene are produced by co-expression from pAC-BETA, pAC-DELTA and pAC-EPSILON, respectively, lycopene by co-expression from pAC-LYC and zeaxanthin by co-expression from pAC-ZEAX. Negative controls include strains transformed with only the pAC vectors, but induced with IPTG (Control; top row of pellets). Bottom panel: Quantitative analysis of carotenoid accumulation in liquid-grown cultures. Samples labeled PbLSD and Control are extracts from representatives of the samples shown in the top panel. Relative carotenoid concentration values are shown as an average of three samples each. Significant differences (p values < 0.05) were assessed by student T test and are denoted with an *